Merging into freeways is always a problem and a hazard to everyone involved. Quick acceleration makes highway safer. More pulling power also means less slow trucks on grades and less jams around them.
It is of course irrelevant for the bright future where are no human drivers.
For quantifying discrete objects, you should use "fewer", not "less". "Less" is used for aggregates, continuous media, and numeric values. So, "fewer people", but "less water".
You needn't do this. Some random bloke thought it'd be a good idea years ago, wrote it down in a book. A certain type of pedant says to themselves, oh somebody wrote it down in a book - that's the rule them. Nope.
You can't use fewer in some places, but the insistence that if you can use it then you must is an zombie rule. If "less" sounds right it's fine.
May have been a joke but 20 seconds is still really slow. I had a van that took 13 seconds on paper (although I never actually verified that) and the contents we never in danger of being tossed around.
sound of cargo falling over :P
But serious question: how important is acceleration for trucks?